For Muslim Brotherhood, a Painful Day of Reckoning

CAIRO—A month of deadly conflict between security forces and the mostly Islamist supporters of Egypt's ousted president has battered the country's once-powerful Muslim Brotherhood, leaving it with diminishing prospects for restoring its former pre-eminence.

At least 42 people were killed in clashes around Egypt on Friday, according to officials, in violence set off two days previously when police raids on Muslim Brotherhood protests in Cairo left hundreds dead, in modern Egypt's worst violence in memory. As Brotherhood...